A phase II study of sequential methotrexate and fluorouracil in advanced colorectal cancer.

Twenty-nine patients with advanced colorectal cancer were treated with methotrexate (MTX) 200 mg/m2 followed 1 h later by fluorouracil (FU) (1000 mg/m2) and 24 h later by oral leucovorin 20 mg every 6 h for six doses. The cycle was repeated every 2 weeks. Among the 25 evaluable patients there were 2 complete responses (confirmed by liver scan) and 5 partial responses. Although hematological toxicity was mild, there were four episodes of nonfatal sepsis. The majority of patients developed an erythematous scaly rash on the palms and soles plus eye irritation after six courses of chemotherapy. In addition, the sequential MTX-FU had to be discontinued in 6 of the 7 responders because of (a) severe chills, (b) severe hyperpigmentation, or (c) neurologic complications (ataxic gait or disorientation). These results indicate that this sequential MTX-FU has modest activity in colorectal cancer but is associated with moderately severe toxicity. Only randomized trials of FU alone versus sequential MTX-FU can determine whether sequential MTX-FU has a therapeutic advantage over FU alone in the treatment of advanced colorectal cancer.